Anyone have any ideas/suggestions as to how to cover the “legs” on the trestle once it is screwed down?
Like this one?
Once they are firmly in place, the leg bases can be covered with scenic material. Depending on the terrain, you could use plaster covered with shrubbery, talus (small rocks) or pavement made from plaster or Durham’s Water Putty in an urban area.
I’ve used them too, in HO scale. I just cut off the web, painted them, added a concrete base (wood) and glued them down. I used super glue to glue the supports to the wood base.
You can see a couple under the upper tresstle near the signal.
The prototype railroads would use “fill” under their roadbed to gain the desired elevations. Depending on the region you are trying to model, look for examples of this type of engineering.